Embodiments consistent with the present invention generally relate to a semiconductor device and a method for manufacturing the same, and more specifically, to a semiconductor device having a capacitor and a method for manufacturing the same.
Due to the increased demand in the capacity of semiconductor memory devices, which include capacitors, various technologies have been developed to increase the capacitance of the capacitor.
In general, a capacitor has a structure, which includes a dielectric film formed between a bottom electrode (or a storage node) and a top electrode (or a plate electrode). Capacitance of the capacitor is proportional to an electrode surface area and a dielectric constant of the dielectric film, and is inversely proportional to an interval of the top and bottom electrodes, that is, a thickness of the dielectric film.
In order for the capacitor to have a high capacitance, various methods can be employed to fabricate the capacitor. For example, one can use a dielectric film having a large dielectric constant, reduce the thickness of the dielectric film, increase the electrode surface area, or reduce the distance between the top and bottom electrodes.
However, as the device size becomes smaller due to increased integration of the semiconductor memory device, it is difficult to fabricate a capacitor with a small size, yet securing sufficient capacitance.
To secure a sufficient capacitance, researchers have focused their attention to the structure of the bottom electrode. As a result, a concave type (or cylinder type) capacitor having a three-dimensional structure has been developed.
Recently, the cylinder type capacitor using both an external surface and an internal surface as a node surface has been widely used, rather than using only the internal surface as a node surface. Generally, the cylinder type capacitor is formed by a dip-out process.
Although the capacitance of a capacitor may be increased by increasing the height of the capacitor, a capacitor leaning phenomenon may occur as a result of the height increase.